Valve seat finishing devices

ABSTRACT

A valve seat finishing device for use with a spindle having a drive is provided. The valve seat finishing device includes a driver, a valve seat finishing tool, an annular finishing surface on the tool, and a non-dressable super abrasive on the annular finishing surface. The driver has a centering portion and a drive portion. The centering portion is received in a receiving portion of the drive and the drive portion is received in the drive so that rotation of the spindle causes the socket drive to concentrically rotate the driver. The valve seat finishing tool is threadably secured to the driver. The non-dressable super abrasive provides a lapped finish to the valve seat.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure is related to internal combustion engines. Moreparticularly, the present disclosure is related to devices for finishingthe surface of valve seats in such internal combustion engines.

2. Description of Related Art

Internal combustion engines include an intake valve assembly and anexhaust valve assembly. During operation of the engine, the valveassemblies allow air-fuel mixtures and combustion by-products toselectively enter and exit the combustion chamber of the engine in aknown manner.

The valve assemblies include a poppet valve received in the cylinderhead of the internal combustion engine. The poppet valve has a sealingface and a valve stem. The cylinder head includes a valve seat and avalve guide. The valve stem is slideably received in the valve guide sothat the sealing face can selectively seal against and unseal from thevalve seat.

In internal combustion engines, it is desired that the cylinders beairtight when the valve assemblies are closed to assure efficient fuelconsumption and transfer of power. This airtightness is achieved by,among other things, assuring that the valve faces match the valve seats.Since the valve faces and valve seats are subject to wear and otherdegrading factors that affect the surface finish, the face and seat areoften repaired to re-establish the quality of the seal.

In order to provide the desired tolerance between the valve face and thevalve seat, a machining or cutting operation is typically performed. Themachining or grinding operation removes the outer surface of the seatand face to expose a relatively smooth contact surface. Machining orgrinding operations on the valve face are relatively straightforward dueto the high mobility of the poppet valve.

However, machining and/or grinding operations on the valve seat are madedifficult by the size and weight of the cylinder head. Currently, valveseat and guide machines are available for performing the machiningand/or cutting operation of the cylinder head, which has greatlyincreased the ease with which the valve seat and valve guide can berefinished.

Unfortunately, the machining and/or grinding operation alone usuallydoes not provide sufficient surface finish to the valve seat. Thus,after machining and/or grinding the valve seats, it is required that thevalve seat be manually finished to the desired surface finish, whichrequires removal of the cylinder head from the machine and, thus,increases the cost and time associated with such repairs.

Moreover, the machine tools used in such machine operations requirefrequent re-sharpening, while the grinding tools used in such grindingoperations require frequent re-dressing. Thus, the valve seat and guidemachines, while adding precision to the process, can increase the timerequired to resurface the valve seat due to constant repair and dressingof the machine and grinding tools, respectively.

Accordingly, it has been determined by the present disclosure that thereis a need for devices that finish the surfaces of valve seats whileovercoming, alleviating, and/or mitigating one or more of theaforementioned and other deleterious effects of the prior art.

BRIEF SUMMARY OF THE INVENTION

A valve seat finishing device for use with a spindle having a drive isprovided. The valve seat finishing device includes a driver, a valveseat finishing tool, an annular finishing surface on the tool, and anon-dressable super abrasive on the annular finishing surface. Thedriver has a centering portion and a drive portion. The centeringportion is received in a receiving portion of the drive and the driveportion is received in the drive so that rotation of the spindle causesthe socket drive to concentrically rotate the driver. The valve seatfinishing tool is threadably secured to the driver. The non-dressablesuper abrasive provides a lapped finish to the valve seat.

In some embodiments, the valve seat finishing device includes a balldriver and a valve seat finishing tool threadably secured to the balldriver. The ball driver has a centering surface and a drive pin. Thecentering surface is received in a receiving surface of the socket driveand the drive pin received in a drive pin slot of the socket drive sothat rotation of the spindle causes the socket drive to concentricallyrotate the ball driver. The valve seat finishing tool provides a lappedfinish to the valve seat.

In other embodiments, the valve seat finishing device includes a conedriver and a valve seat finishing tool threadably secured to the conedriver. The cone driver has a cone-shaped surface and a key. Thecone-shaped surface is received in a receiving surface of the tapereddrive and the key is received in a keyway of the tapered drive so thatrotation of the spindle causes the tapered drive to concentricallyrotate the cone driver. The valve seat finishing tool provides a lappedfinish to the valve seat.

A method of finishing a valve seat is also provided. The method includesoperating a machine to rotate a spindle so as to machine and/or grindthe valve seat; connecting a valve seat finishing tool to the spindle,the valve seat finishing tool having an annular finishing surface at adesired angle with a plated super abrasive thereon; and operating themachine to rotate the spindle so as to finish the valve seat to a lappedfinish.

The above-described and other features and advantages of the presentdisclosure will be appreciated and understood by those skilled in theart from the following detailed description, drawings, and appendedclaims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is top perspective view of a prior art valve seat and guidemachine;

FIG. 2 is a partially exploded illustration of an exemplary embodimentof a valve seat finishing device according to the present disclosure foruse with the machine of FIG. 1;

FIG. 3 is an alternate exemplary embodiment of the valve seat finishingdevice of FIG. 2; and

FIG. 4 is a partially exploded illustration of an alternate exemplaryembodiment of a valve seat finishing device according to the presentdisclosure for use with the machine of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and in particular to FIG. 1, an exemplaryembodiment of a prior art valve seat and guide machine 10 is shown.Machine 10 is shown in use with one or more valve seats 12 defined in acylinder head 14 of an internal combustion engine (not shown). Machine10 includes is configured to move a spindle 16 in three axes, namely anx-axis 18, a y-axis 20, and a z-axis 22, as well as to rotate thespindle about the x-axis 18.

In such prior art machines 10, spindle 16 is configured to rotate achuck or drive 26 having a machining or grinding tool (not shown)secured therein so as to machine or grind seats 12 and/or valve guides24. Unfortunately, the ground surface finish and machined surface finishis typically not sufficient to provide a leak proof seal to valve seat12.

Advantageously, the present disclosure provides a valve seat finishingdevice 30 shown in FIGS. 2 and 3. Device 30 is configured to provide alapped finish to valve seat 12, which is sufficient to provide a leakproof seal to valve seat 12. Moreover, device 30 can easily be used withmachine 10 and does not require dressing before use as with bondedabrasive grinding wheels. As used herein, the term “lapped finish” shallmean a surface roughness of between about 5 to about 35 root mean square(“RMS”) as described in ASME B46.1 and measured in microinches.

In embodiments where drive 26 is a socket drive 32, device 30 includes aball driver 34, a valve seat finishing tool 36, and a pilot shaft 38. Insome embodiments, system 30 further includes a compression spring 40.For purposes of clarity, ball driver 34 and tool 36 are illustrated ascross sections.

Socket drive 32, ball driver 34, and pilot shaft 38 can be made of anymaterial having sufficient hardness and heat resistance. In someembodiments, socket drive 32 and ball driver 34 are made of heat treatedsteel having a black oxide coating, while pilot shaft 38 is made ofcarbide or tool steel.

Socket drive 32 is configured for securement to spindle 16 of machine 10so that rotation of the spindle about the x-axis 18 is imparted to thesocket driver. For example, socket drive 32 can include a flattened end42 drivingly received by spindle 16.

Socket drive 32 includes a receiving surface 44 and a drive pin slot 46having an open bottom end 48. Ball driver 34 includes a centeringsurface 54 and a drive pin 56. In use, receiving surface 44 receivescentering surface 54 so that ball driver 34 is centered within socketdrive 32 and so that drive pin 56 is received in drive pin slot 46. Inthis manner, ball driver 34 is releasably and concentrically secured tosocket drive 32 so that rotation of spindle 16 causes socket drive 32 torotate ball driver 34 about the x-axis 18.

It should be recognized that device 30 is illustrated by way of examplehaving receiving surface 44/drive pin slot 46 on socket drive 32 andcentering surface 54/drive pin 56 on ball driver 34. Of course, it iscontemplated by the present disclosure for ball driver 34 to includereceiving surface 44/drive pin slot 46 and socket drive 32 to includecentering surface 54/drive pin 56 or any combinations thereof.

Ball driver 34 includes a first threaded portion 50, which is threadablyengaged with a second threaded portion 52 of tool 36. In addition, balldriver 34 includes a first bore 58, while tool 36 includes a second bore60. Bores 58, 60 are configured for receipt of pilot shaft 38 therein sothat the pilot shaft is concentric to ball driver 34 and tool 36.

In some embodiments, pilot shaft 38 can freely spin within bores 58, 60,which results in a so called “dead-pilot” shown in the embodiment ofFIG. 3. In other embodiments shown in the embodiment of FIG. 3, balldriver 34 further includes one or more threaded set-screw openings 62 sothat the ball driver can be releasably secured to pilot shaft 38 by wayof one or more set screws (not shown), which results in a so called“live pilot”.

Tool 36 includes an annular finishing surface 64 having a plated superabrasive 66 thereon. In an exemplary embodiment, tool 36 is made of mildtool steel. In another exemplary embodiment, plated super abrasive 66that can be a nickel plated diamond layer, a plated cubic-boron-nitride(CBN) layer, and any combinations thereof. Plated super abrasive 66 hasa grit of above about 150 grit, with between about 180 to about 320 gritbeing preferred, and about 240 grit being most preferred.

Advantageously, plated super abrasive 66 eliminates the need fordressing before use as is required when using grinding wheels andeliminates the need for sharpening before use as is required when usingmachining tools.

In the preferred embodiment, annular finishing surface 64 has an angle(θ) with respect to the x-axis 18, where the angle θ corresponds to adesired angle of valve seat 12.

In use, pilot shaft 38 is configured for receipt in a valve stem guide24 of cylinder head 14 so that the pilot shaft rotates about the x-axis18 and moves along the x-axis. Thus, pilot shaft 38 maintains device 30concentrically aligned with valve seat 12 throughout the finishingprocess. Spring 40, when used, can assist in maintaining plated superabrasive 66 of tool 36 out of contact with seat 12 until device 30 is ata desired speed, at which time compression of spring 40 along the x-axis18 results in plated super abrasive 66 contacting and finishing seat 12.In the illustrated embodiment, spring 40 rests on a bottom face 68 oftool 36.

As it is desired for tool 36 to provide a lapped finish to valve seat12, it is contemplated by the present disclosure for the desired speedof tool 36 to be limited to between about 30 to about 150 revolutionsper minute, with between about 40 to about 50 revolutions per minutebeing preferred. Further, it is contemplated by the present disclosurefor the cutting force of tool 36 (e.g., the force with which tool 36 isapplied to valve seat 12) to be limited to between about 0 to about 10pounds, with between about 1 to about 5 pounds being preferred. In thismanner, tool 36 provides a typical lapping process having low cuttingspeed and low cutting forces, providing for shallow penetration of fineabrasive grains without generating significant heat to limit thermaldamage.

In the embodiment of valve seat finishing device 30 shown in FIG. 3,device 30 is configured for use where drive 26 is a quick connect socketdrive (not shown) as is commercially available from Rottler. Here, balldriver 34 further includes a retaining rim 70. Rim 70 is configured toensure that ball driver 34 is maintained in the quick connect socketdrive. Since ball driver 34 and tool 36 are connected to spindle 16, theneed for compression spring 40 can, in some instances, be eliminated.

Referring now to FIG. 4, another alternate exemplary embodiment of avalve seat finishing device 130 according to the present disclosure isshown. Here, component parts performing similar or analogous functionsare labeled in multiples of one hundred with respect to the embodimentof FIGS. 2 and 3. Device 130 is configured for use with machine 10 wheredrive 26 is a tapered drive 132.

Device 130 includes a cone driver 134, tool 36, and pilot shaft 38. Insome embodiments, system 130 further includes a compression spring 40.For purposes of clarity, cone driver 134 and tool 36 are illustrated ascross sections.

Tapered drive 132, cone driver 134, and pilot shaft 38 can be made ofany material having sufficient hardness and heat resistance. In someembodiments, tapered drive 132 and cone driver 134 are made of heattreated steel having a black oxide coating, while pilot shaft 38 is madeof carbide or tool steel.

Tapered drive 132 is configured for securement to spindle 16 of machine10 so that rotation of the spindle about the x-axis 18 is imparted tothe tapered driver.

Tapered drive 132 includes a receiving surface 144 and a keyway 146.Cone driver 134 includes a cone-shaped surface 154 and a key 156. Inuse, receiving surface 144 receives cone-shaped surface 154 so that conedriver 134 is centered within tapered drive 132 and so that key 156 isreceived in keyway 146. In this manner, cone driver 134 is releasablyand concentrically secured to tapered drive 132 so that rotation ofspindle 16 causes tapered drive 132 to rotate cone driver 134 about thex-axis 18. In some embodiments tapered drive 132 also includes a bottomcap 170 threadably received on a bottom end 148. In this manner, conedriver 134 is maintained in tapered drive 132 by cap 170. Since conedriver 134 and tool 36 are connected to spindle 16 by cap 170, the needfor compression spring 40 can, in some instances, be eliminated.

In some embodiments, key 156 can be removably secured to cone driver 134by one or more set screws 172. In this manner, key 156 can be removedfrom cone driver 134 and replaced with a new, undamaged key 156.

Cone driver 134 includes a first threaded portion 150, which isthreadably engaged with a second threaded portion 52 of tool 36. Inaddition, cone driver 134 includes a first bore 158, tool 36 includes asecond bore 60, and bottom cap 170 includes a third bore 174. Bores 158,60, 174 are configured for receipt of pilot shaft 38 therein so that thepilot shaft is concentric to cone driver 134 and tool 36.

In some embodiments, pilot shaft 38 can freely spin within bores 158,60, 174 which results in a so called “dead-pilot”. In other embodiments,cone driver 134 further includes one or more threaded set screw openings162 so that the cone driver can be releasably secured to pilot shaft 38by way of one or more set screws (not shown), which results in a socalled “live pilot”.

In use, pilot shaft 38 is configured for receipt in valve stem guide 24of cylinder head 14 so that the pilot shaft rotates about the x-axis 18and moves along the x-axis. Thus, pilot shaft 38 maintains valve seatfinishing device 130 concentrically aligned with valve seat 12throughout the finishing process. Spring 40, when used, can assist inmaintaining plated super abrasive 66 of tool 36 out of contact with seat12 until valve seat finishing device 130 is at a desired speed, at whichtime movement of device 130 along the x-axis 18 results in compressionof spring 40 so that plated super abrasive 66 contacting and finishingseat 12. In the illustrated embodiment, spring 40 rests on bottom face68 of tool 36.

Advantageously, valve seat finishing devices 30 and 130 allow anoperator to use machine 10 to use known methods to machine and grindvalve seat 12, and then to quickly insert socket drive 32 or tapereddrive 132 into the spindle 16. With valve seat finishing devices 30 and130, the operator can provide a lapped finish to valve seat 12 usingmachine 10 such that no additional manual operations are required.

In use, an operator first mounts cylinder head 14 of an internalcombustion engine in machine 10. Then, the operator uses machine 10 tomachine and/or grind valve seat 12. In some embodiments, valve seatfinishing devices 30, 130 are configured to receive a threaded grindingwheel (not shown) on threads 50, 150 in place of tool 36.

When using socket drive 32, the operator secures tool 36 to ball driver34 via threads 50, 52. In addition, the operator inserts pilot shaft 38through bores 58, 60 and secures the pilot shaft to ball driver 34 usingset screws in set screw openings 62. However, when using tapered drive132, the operator secures tool 36 to cone driver 134 via threads 150,52. In addition, the operator inserts pilot shaft 38 through bores 158,60, 174 and secures the pilot shaft to cone driver 134 using set screwsin set screw openings 162.

After machining and/or grinding valve seat 12, the operator securessocket drive 32 or tapered drive 132 to machine 10, slides spring 40over pilot shaft 38, and inserts the pilot shaft into valve stem guide24. In this position, spring 40 prevents plated super abrasive 66 fromcontacting valve seat 12. The operator activates machine 10 so as torotate spindle 16 and, thus tool 36 about x-axis 18. Once tool 36attains a desired speed, the operator moves tool 36 along x-axis 18 andinto contact with valve seat 12 so that plated super abrasive 66finishes the valve seat to the desired lap finish.

In use, valve seat finishing tool 36 provides a super abrasive seat lapwhich can be used directly on machine 10 and, thus, eliminates the needto remove cylinder head 14 from machine 10 for further processing. Inthis manner, tool 36 reduces the time and cost of refinishing cylinderhead 14.

It should also be noted that the terms “first”, “second”, “third”,“upper”, “lower”, and the like may be used herein to modify variouselements. These modifiers do not imply a spatial, sequential, orhierarchical order to the modified elements unless specifically stated.

While the present disclosure has been described with reference to one ormore exemplary embodiments, it will be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of thepresent disclosure. In addition, many modifications may be made to adapta particular situation or material to the teachings of the disclosurewithout departing from the scope thereof. Therefore, it is intended thatthe present disclosure not be limited to the particular embodiment(s)disclosed as the best mode contemplated, but that the disclosure willinclude all embodiments falling within the scope of the appended claims.

1. A valve seat finishing device for use with a spindle having a socketdrive, comprising: a ball driver having a centering surface and a drivepin, said centering surface being receivable in a receiving surface ofthe socket drive and said drive pin being receivable in a drive pin slotof the socket drive so that rotation of the spindle causes the socketdrive to concentrically rotate said ball driver; and a valve seatfinishing tool threadably secured to said ball driver, said valve seatfinishing tool being configured to provide a lapped finish to the valveseat.
 2. The valve seat finishing device of claim 1, wherein said valveseat finishing tool comprises a non-dressable super abrasive.
 3. Thevalve seat finishing device of claim 1, further comprising a pilot shaftsecured in a first bore of said ball driver and a second bore of saidvalve seat finishing tool so that said pilot shaft is concentric to saidball driver and said valve seat finishing tool.
 4. The valve seatfinishing device of claim 3, further comprising a compression springdisposed about said pilot shaft spring against a bottom face of saidvalve seat finishing tool.
 5. The valve seat finishing device of claim3, wherein said ball driver comprises one or more threaded set screwopenings so that said ball driver can be releasably secured to saidpilot shaft by way of one or more set screws.
 6. The valve seatfinishing device of claim 1, wherein said valve seat finishing toolcomprises an annular finishing surface.
 7. The valve seat finishingdevice of claim 6, wherein said annular finishing surface has an anglethat corresponds to a desired valve seat angle.
 8. The valve seatfinishing device of claim 6, wherein said valve seat finishing toolcomprises a plated super abrasive on said annular finishing surface. 9.The valve seat finishing device of claim 8, wherein said plated superabrasive comprises a nickel plated diamond layer, a platedcubic-boron-nitride (CBN) layer, and any combinations thereof.
 10. Thevalve seat finishing device of claim 8, wherein said plated superabrasive comprises a grit above about
 150. 11. The valve seat finishingdevice of claim 8, wherein said plated super abrasive comprises a gritbetween about 180 to about
 320. 12. The valve seat finishing device ofclaim 8, wherein said plated super abrasive comprises a grit of about240.
 13. The valve seat finishing device of claim 1, wherein said balldriver further comprises a retaining rim.
 14. A valve seat finishingdevice for use with a spindle having a tapered drive, comprising: a conedriver having a cone-shaped surface and a key, said cone-shaped surfacebeing receivables in a receiving surface of the tapered drive and saidkey being receivable in a keyway of the tapered drive so that rotationof the spindle causes the tapered drive to concentrically rotate saidcone driver; and a valve seat finishing tool threadably secured to saidcone driver, said valve seat finishing tool being configured to providea lapped finish to the valve seat.
 15. The valve seat finishing deviceof claim 14, further comprising a pilot shaft secured in a first bore ofsaid tapered driver and a second bore of said valve seat finishing toolso that said pilot shaft is concentric to said cone driver and saidvalve seat finishing tool.
 16. The valve seat finishing device of claim15, further comprising a compression spring disposed about said pilotshaft spring against a bottom face of said valve seat finishing tool.17. The valve seat finishing device of claim 15, wherein said conedriver comprises one or more threaded set screw openings so that saidcone driver can be releasably secured to said pilot shaft by way of oneor more set screws.
 18. The valve seat finishing device of claim 14,wherein said valve seat finishing tool comprises an annular finishingsurface having a plated super abrasive on said annular finishingsurface.
 19. The valve seat finishing device of claim 18, wherein saidplated super abrasive comprises a nickel plated diamond layer, a platedcubic-boron-nitride (CBN) layer, and any combinations thereof.
 20. Thevalve seat finishing device of claim 14, wherein said key is removablysecured to said cone driver by one or more set screws.
 21. A method offinishing a valve seat, comprising: operating a machine to rotate aspindle so as to machine and/or grind the valve seat; connecting a valveseat finishing tool to said spindle, said valve seat finishing toolhaving an annular finishing surface at a desired angle with a platedsuper abrasive thereon; and operating said machine to rotate saidspindle so as to finish the valve seat to a lapped finish to the valveseat.
 22. A valve seat finishing device for use with a spindle having adrive, comprising: a driver having a centering portion and a driveportion, said centering portion being receivable in a receiving portionof the drive and said drive portion being receivable in the drive sothat rotation of the spindle causes the socket drive to concentricallyrotate said driver; a valve seat finishing tool threadably secured tosaid driver; annular finishing surface being defined on said valve seatfinishing tool; and a non-dressable super abrasive on said annularfinishing surface, said non-dressable super abrasive being configured toprovide a lapped finish to the valve seat.
 23. The valve seat finishingdevice of claim 22, wherein said non-dressable super abrasive comprisesa nickel plated diamond layer, a plated cubic-boron-nitride (CBN) layer,and any combinations thereof.